Rounding and Truncating
ROUND, CEIL, FLOOR and TRUNC.
Why Rounding Matters
When working with numbers in SQL, you often get results with many decimal places. For example, dividing 10 by 3 gives 3.3333333...
SQL provides built-in functions to control how many decimal places you display or store: ROUND, CEIL, FLOOR, and TRUNC. These are essential for presenting clean financial figures, measurements, and statistics.
SELECT 10.0 / 3.0 AS raw_result;ROUND: Basic Usage
The ROUND() function rounds a number to a specified number of decimal places. It follows standard rounding rules: digits 5 and above round up, digits below 5 round down.
The syntax is: ROUND(number, decimal_places). If you omit the second argument, it rounds to the nearest whole number.
SELECT
ROUND(3.14159, 2) AS two_decimals,
ROUND(3.14159, 0) AS zero_decimals,
ROUND(3.14159) AS no_arg;All lessons in this course
- Arithmetic and Operators
- Rounding and Truncating
- Integer vs Decimal Division
- Useful Math Functions